The invention is an improvement in sports shoes, and in particular tennis shoes, that provides improved support of the foot during active sports.
Tennis and other active sports can impart severe stresses to the bones, ligaments, and muscles of the foot, particularly during stopping, turning, and lateral movements on the court. During such movements, the foot tends to move in the shoe. When this happens, the foot muscles and muscles in the leg tend to work harder to try to compensate for the movement. This causes fatigue, and ankle or knee injuries can occur due to the strain of overcompensating muscles. It is desirable that tennis footwear, as well as other sports shoes, be designed to support the foot in the appropriate areas to prevent this excess movement.
U.S. Pat. No. 2,539,761 to Whitman discloses a sneaker that includes flexible retention straps on either side of the foot to prevent the foot from sliding forward in the shoe, and to provide side balance. The bottoms of the straps are secured to the sole in positions immediately to the rear of the heads of the first and fifth metatarsal bones of the foot, and extend rearwardly and upwardly over the instep (arch).
U.S. Pat. No. 3,768,182 to Powers discloses a shoe with soft side walls and a pair of reinforcing overlays on either side of the shoe. The bottom of the overlay extends between a point immediately behind the ball of the foot to a point immediately behind the arch, with a cutout portion therebetween. The overlays extend forwardly and upwardly from their bottom portions and cover a substantial part of the forward portion of the foot.
When the foot moves in the shoe, for example when stopping or turning, to the extent that these known reinforcing members constrain movement of the foot, they do so by exerting a force on the arch, in a direction perpendicular to the longitudinal direction of the foot. Also, these straps are designed principally to support the bones and joints only in the forward part of the foot. Furthermore, the degree of lateral support such straps can provide is limited. It would be desirable to provide improved lateral support to the principal stress-bearing bones, to limit the movement thereof, and to provide such support both in the forward and rear portions of the foot.